Memory expander

The Mega-Cart can be used as configurable Memory (RAM) expander/unexpander. By using the on-screen menus, you can select a specific memory configuration for the Vic-20's BASIC mode without having to remove the cartridge and flip dip-switches.

There are many ways to select a memory configuration. The easiest is to hold a function key on boot:

In addition, the Early Startup menu contains two special submenus (Normal & Soft Reset) that allow you to start up the Vic-20 with various memory configurations (with relative characteristics).

The Normal Reset sub-menu contains many memory configurations (some offering additional utilities like Super expander or Programmer's Aid). If you select a configuration with 32K in Normal Reset mode, any ROM image on BLK5 will be automatically started (if previously loaded in memory).

If you prefer, you can lock this sub-menu and always start the Mega-Cart from the Normal Reset menu instead of the default Early Startup menu. To do this just hold the "4" key on boot. You can re-enable the Early Startup menu by holding down the “0” (zero) key while booting.

The Soft Reset (No Auto) sub-menu contains memory configurations with 32K RAM always present (Read/Write or Read Only). Note: if you select any of these configurations, ROM images on BLK5 will not be started even if previously loaded into memory (like with normal Vic-20 RAM expanders). In this way you can inspect and (according to the selected RAM configuration) even edit the memory using a monitor or any other tool. You can at any time start a ROM image on BLK5 by typing SYS64802 (standard Vic-20 soft reset call).

If you prefer, you can lock this sub-menu and always start the Mega-Cart from the Soft Reset (No Auto) menu instead of the normal Early Startup Menu. To do this just hold the "5" key on boot. You can re-enable the normal Early Startup menu by holding down the “0” (zero) key while booting.